Original URL: http://www.theregister.co.uk/2007/06/26/cryptography_patents/

Voltage secures patents on identity-based encryption

Assumes you are who you say you are

By Bill Ray

Posted in Security, 26th June 2007 12:01 GMT

Voltage Security has been granted five patents covering the core functionality of their "identity-based" encryption products, though they're keen to share the technology with everyone on a reasonable and non-discriminatory basis.

Most public-key encryption systems require an exchange of keys before data can be encrypted, but Voltage takes advantage of Elliptic Curve Cryptography (ECC) to create a system where knowing someone's email address, or any other unique identifier, gives access to their public key and thus enables encrypted messages to be sent to that person.

To massively simplify: ECC provides a large range of key pairs, and the unique identifier is used to select which pair should be used to communicate with that person. To encrypt a message the sender can calculate the public key from the unique identifier; the recipient presents the same identifier to the Voltage server to get the private component and decrypt the message.

Voltage provides a much more comprehensive description.

Anyone familiar with cryptography will have noticed that this means the Voltage server has copies of all the private keys - unlike PGP or its brethren - but Voltage reckons the advantage of not requiring the recipient to sign up first will drive greater use of encrypted communications and as long as you trust Voltage then there's no problem.

More serious is the fact that few people see the need to encrypt their communications. Users have proved themselves reluctant to take even the smallest step without some form of company mandate, and unless they can be scared into realising how insecure internet communication is then patents on identity-based encryption might not be worth the paper they're written on.®